Rapid advances in electronics and communication technologies, driven by immense customer demand, have resulted in the widespread adoption of mobile devices. Some estimates indicate that (as just three examples) the United States, Italy, and the United Kingdom have more mobile phones in use in each country than there are people living in those countries. Vast communication networks support communications by mobile devices across sprawling geographical expanses. Increasing the capability and efficiency of these communication networks may result in even further use of mobile devices.